More particularly, the invention is directed to a multi-component closure cap operating as a flip-top device and in which a specially structured and positioned hinge assembly ensures that in the open position of a cap, the dispensing port is not only opened but is completely unobstructed visually so as to provide unimpaired monitoring of the dispensing port during delivery of product therefrom. In its more general features, the closure of the invention is of the broad type which has a top panel and an annular skirt, the latter being threadedly or otherwise secured to the neck of the dispensing container. The top or top panel is formed with a through transverse port which is the outlet or orifice from which the contents of the container are dispensed. In one embodiment of the invention the top or top panel is integrally formed with the depending skirt to constitute a unitary component of the closure assembly. A second physical element of the closure consists of a cover, cap or lid which carries on its undersurface, as a projection therefrom, a plug for entry into to seal the dispensing port in the top wall of the skirt and wall unit. Again, tops or caps of generally similar overall structure and function are known in the art.
In general, the prior art top or cap which overlies to seal the dispensing port is hingedly secured to the closure itself at an upper peripheral edge by means of a live hinge or thinned web. In other prior art structures the hinge which secures the cap or cover constitutes a combination of a live hinge web in conjunction with augmenting, cooperating connecting arms which bridge between the principal closure component and the pivotally mounted closure cap, the arrangement being described in the prior art as imparting a "snap action" to the hinge assembly.
The shortcomings of thinned web hinges or "live" hinges have been conceded in the prior art, and structures have been devised for overcoming the elasticity of such hinges which tend prematurely to return the lid of the closure to a closed position when it has been opened. One approach toward resolving this deficiency in integrally formed hinges is to provide the lid with a leg or strut having a length such that the end of the leg engages and bears upon the lid itself during the hinge operation so as to impart a toggle-like action to the closure cap as the leg acts to stretch the hinge web.
Although it has long been recognized that it would be desirable and advantageous to provide a closure having a hinged cap or lid which would be pivotal so as fully to expose the pouring or discharge orifice of the container and which would, at the same time, assume and hold the particular functional position impressed upon the lid, no completely satisfactory structure has heretofore been devised. The closures utilizing lids secured and manipulated through thinned webs or "live" hinges have either failed to maintain a positive retracted position of the lid in its "open" position, or have incorporated auxiliary structures which have in themselves been deleterious to the life of the web hinge. Many of the prior art structures have supported the pivotal cover or lid in a manner which has interfered with the visual perception and monitoring of the discharge port or orifice during the dispensing of product from the container itself. In other prior art closures the lid or cover includes a hinge portion of which extends beyond the diameter limits of the cap itself, interfering with the operation of automatic capping machinery.
It is, accordingly, a principal aim of the present invention to cure the shortcomings of prior art structures and to provide, in a container closure assembly, an improved hinge support for the overlying cap or lid, the structure being effective to ensure simple and reliable operation and to present the lid, in its open position, in a configurational mode in which there is no impairment or impediment to the viewing of the dispensing orifice even upon extreme tilting of the container as may normally occur during the dispensing of products from the container storage chamber, and in which there is no impediment to the use of automatic capping equipment.